自家无乳链球菌乳房炎疫苗使用效果评价

本研究采集某奶牛场全群泌乳牛的奶样,经美国加利福尼亚隐性乳房炎测试法(CMT)检测后,对阳性奶样进行细菌培养并鉴定出该场隐性乳房炎的主要致病菌,制作自家乳房炎疫苗。通过病原菌检测、隐性乳房炎发病率及体细胞数的变化趋势分析,评估自家乳房炎疫苗的使用效果,以供参考。     

高利多奶牛乳房炎（J5）疫苗的免疫效果试验

对上海市10个规模化奶牛场586头奶牛的抗体效价、体细胞数(SCC)、隐性乳房炎患病情况、细菌总数等进行跟踪监测。以验证高利多奶牛乳房炎(J5)疫苗的免疫效果和免疫期。从免疫前后的血清平均ELISA抗体效价监测结果来看,高利多疫苗三免35d左右,抗体水平达到高峰,是免疫前的5.4倍。三免后150d左右,疫苗的抗体水平基本降到免疫前水平。从免疫前后SCC监测结果来看,高利多疫苗免疫后奶牛的平均体细胞数呈逐渐下降趋势,免疫组和对照组体细胞数量差异不显著(P>0.05)。从免疫前后奶样中细菌总数监测结果来看,免疫前后免疫组和对照组奶样平均细菌总数均有下降趋势,免疫组和对照组平均细菌总数差异显著(P<0.05)。从免疫前后隐性乳房炎的发病情况来看,隐性乳房炎发病牛数及发病乳区数免疫组与对照组在免疫前后变化不明显,试验组与对照组相比,差异不显著(P>0.05),但是革兰氏阴性杆菌引起隐性乳房炎发病情况免疫组要比未免疫组低,经检验差异显著(P<0.05)。高利多疫苗在CCM免疫保护上具有一定的免疫效果,但在预防新生犊牛腹泻上效果不理想。     

重组溶葡萄球菌酶对奶牛隐性乳房炎的治疗试验

北京某牛场24头经BLT检测为阳性的隐型乳房炎患牛,共发现有32个患病乳区,将24头牛分成4个组,每组6头（8个患病乳区）。分别用重组溶葡萄球菌酶粉200U/乳区、400U/乳区、600U/乳区3个剂量,对照组以注射用头孢噻呋钠0.25g/乳区给药,每天早晚挤奶后乳池灌注,共用4d,研究不同剂量重组溶葡萄球菌酶对奶牛隐性乳房炎的治疗效果。结果显示,3个剂量重组溶葡萄球菌酶均能降低牛奶中的体细胞数。200U剂量组降低隐性乳房炎牛奶中的体细胞的作用略优于头孢噻呋钠（P〉0.05）;400U、600U剂量组降低隐性乳房炎牛奶中的体细胞的作用显著优于头孢噻呋钠（P〈0.01）;400U、600U剂量组降低隐性乳房炎牛奶中的体细胞的作用无差异（P〉0.05）。重组溶葡萄球菌酶是治疗奶牛隐性乳房炎的安全有效的药物。     

几种多联灭活疫苗对奶牛乳房炎免疫效果的观察

通过对奶牛乳房炎蜂胶、油佐剂、铝胶佐剂多联灭活苗的效果检测,表明铝胶佐剂多联灭活苗免疫效果最佳,该疫苗能有效的降低隐性乳房炎牛乳的体细胞数,减少临床型奶牛乳房炎的发病率,提高牛奶的品质。     

乳房炎对奶牛产奶量的影响

为了研究乳房炎对奶牛产奶量的影响,收集了西安某奶牛场的620头荷斯坦奶牛完整记录的全年报告中体细胞数据、生产性能和兽医记录,对比分析不同体细胞数对奶牛胎次奶量﹑日产奶量的影响;结果表明,临床乳房炎极显著降低奶牛305d奶量,而在泌乳盛期患病的牛305d奶量减低可达32.5%。隐性乳房炎对奶牛产奶量的影响随患病程度加重而增大。平均体细胞数20万/mL,胎次奶量就会显著较少,而体细胞数50万/mL,胎次奶量极显著降低。奶牛泌乳盛期患隐性乳房炎比泌乳中后期患隐性乳房炎对产奶量影响更大。     

乳房炎的治疗试验报告

本试验通过检测奶站大桶牛奶的体细胞数和细菌数．并通过CMT检测，检测奶牛隐性乳房炎的发病率和乳区发病率．统计目前奶站奶牛乳房炎发病严重情况；本试验还比较乳房炎防治办法和效果，通过对照使用乳头消毒药．使用各种常见药物治疗传染性乳房炎．从而达到控制牛奶中体细胞数和微生物数，提高牛奶质量的目的。     

乳头药浴涂膜剂对奶牛乳房炎的临床疗效

为观察乳头药浴涂膜剂对奶牛隐性乳房炎的预防效果,选择隐性乳房炎奶牛60头,随机分为5组,每组12头。试验Ⅰ组为对照组,Ⅱ组为4%次氯酸钠组,Ⅲ组为0.5%洗必泰组,Ⅳ组为1%碘伏组,Ⅴ组为药浴涂膜剂浸组。在第0、30、60、90天采用SCC法和CMT法检测牛乳中体细胞数,并记录临床型奶牛乳房炎的发病数和发病率,同时记录各组奶牛泌乳总量和平均泌乳量。结果:同对照组相比,各试验组均能显著降低隐性乳房炎病牛体细胞数,且对奶牛乳脂、乳蛋白、乳糖及乳汁p H值、比重、日均泌乳量几乎没有影响。用于预防奶牛隐性乳房炎时,试验Ⅲ、Ⅴ的效果高于试验Ⅱ、Ⅳ组,差异显著(P0.05)。在进行奶牛隐性乳房炎临床治疗试验时,试验Ⅴ组对隐性乳房炎的治愈率和有效率分别为77.78%、88.89%,远高于其他各组。结论:奶牛乳头药浴涂膜剂是一种更适合于进行临床防治奶牛隐性乳房炎的新型奶牛药浴药物,对临床型奶牛乳房炎有较好的预防效果,可以作为预防类药物用于奶牛生产中,降低奶牛乳房炎的发生率。     

乳房炎疫苗对奶牛体细胞数及隐性乳房炎的影响研究

乳房炎是奶牛最主要的疾病之一,每年都会给奶牛业带来巨额的经济损失。针对不同的病原菌,所采取的防控措施也有所不同。本研究引入经欧盟EMA认证的乳房炎大肠杆菌和葡萄球菌二联灭活疫苗,在国内两个奶牛场进行临床测试,验证其临床使用效果。选择地处西安和白银的两个规模化奶牛场,根据奶牛进入干奶期前的奶样检测结果、产量、体况评分等指标,筛选出240头奶牛入选临床测试,按照免疫程序进行免疫后,在产犊后的第2周、第6周、第10周、第14周和第18周分别采奶样检测体细胞数,并对奶样中的细菌进行分离鉴定,确定该疫苗对隐性乳房炎发病状况以及奶牛体细胞数的影响。结果显示,疫苗表现出了优异的效果,特别是第14周,免疫组奶牛的保护率远高于对照组,差异显著(P0.05),其他阶段免疫组的保护率也均高于对照组。两个奶牛场在干奶前1周免疫组的体细胞数和对照组几乎相近,而进入泌乳期后免疫组的体细胞数持续低于对照组,说明试验牛在免疫疫苗后,抗体对病原菌产生了积极作用,缓解了炎症反应,降低了乳中体细胞数。这也从另一方面说明该疫苗具有提高奶牛机体对抗特异性病原的作用。     

乳头液体保护膜“乳宁散”预防奶牛乳房炎效果评价

为观察乳头液体保护膜对奶牛隐性乳房炎的预防效果,选择隐性乳房炎奶牛60头,随机分为5组,每组12头。试验I组为对照组;II组为4%次氯酸钠组;III组为0.5%洗必泰组;IV组为1%碘伏组;V组为奶牛乳头液体保护膜浸组。在0、30、60、90 d采用SCC法和CMT法检测牛乳中体细胞数并记录临床型奶牛乳房炎发病数和发病率,同时记录各组奶牛泌乳总量和平均泌乳量。结果表明：同对照组相比,各试验组均能显著降低隐性乳房炎病牛体细胞数,且对奶牛乳脂、乳蛋白、乳糖及乳汁pH值、比重、日均泌乳量几乎没有影响。用于预防奶牛隐性乳房炎时,试验III、V的效果高于试验II、IV组,差异显著（P〈0.05）。在进行奶牛隐性乳房炎临床治疗试验时,试验V组对隐性乳房炎的治愈率和有效率分别为77.78%和88.89%,远远高于其他各组。说明奶牛乳头液体保护膜是一种更适合于进行临床防治奶牛隐性乳房炎的新型奶牛药浴药物,对临床型奶牛乳房炎有较好的预防效果,可以作为预防类药物用于奶牛生产中,降低奶牛乳房炎的发生率。     

IgG FcRn介导奶牛乳房炎无乳链球菌保护性抗原Sip亚单位疫苗的研究

为研究无乳链球菌Fc-Sip亚单位疫苗的免疫效果,并验证IgGFcRn在奶牛乳腺发生局部免疫过程中的重要作用。本研究采用大肠杆菌原核表达系统,表达了由IgGFcRn介导无乳链球菌保护性表面抗原蛋白(Sip)的融合蛋白Fc-Sip,并与佐剂混合制成Fc-Sip亚单位疫苗。选取干奶前15 d的奶牛进行加州乳房炎检测法(CMT)检测,选取120头CMT(++)以上的奶牛进行分组免疫。通过免疫前后的细菌分离试验、牛奶体细胞数测定、免疫牛血清抗体间接ELISA检测来评价该亚单位疫苗的免疫效果。结果显示,免疫前乳样细菌分菌率为86.6%,无乳链球菌检出率为46.6%;免疫后乳样分菌率降至40%,无乳链球菌检出率降至13.3%,表明Fc-Sip亚单位疫苗不但可以治疗无乳链球菌性奶牛乳房炎,还可以抑制其它奶牛乳房炎致病菌的侵入。首次免疫后60 d,免疫组80%奶牛血清抗体滴度达到1∶2 048～1∶4 096,对照组奶牛抗体滴度一直保持在1∶512。首次免疫后90 d,使用利拉伐牛奶体细胞计数仪测定实验奶牛乳样中的体细胞数,免疫组奶牛乳样体细胞数范围在0.17×10~5个/mL～3.91×10~5个/mL,对照组奶牛乳样体细胞数的范围在4.05×10~5个/mL～7.27×10~5个/mL。免疫组奶牛血清抗体滴度的升高及免疫后牛奶中体细胞数的减少,表明该亚单位疫苗促进了奶牛体液免疫反应和局部免疫反应的发生,也证明该亚单位疫苗具有降低牛奶体细胞数的作用。本研究为奶牛乳房炎无乳链球菌疫苗的研制奠定了基础。     

A clinical trial to evaluate the effectiveness of antibiotic treatment of lactating cows with high somatic cell counts in their milk

OBJECTIVE: To determine the effectiveness of treatment of lactating cows with high somatic cell counts in milk. DESIGN: Randomised clinical trial. METHODS: Single pooled quarter samples of milk were obtained from cows with somatic cell counts above 500,000 cells/mL on fifty farms. Milk samples were cultured for known mastitis bacterial pathogens. Cows were randomly allocated to treated and untreated groups. Treated cows received both intramammary cloxacillin and parenteral erythromycin. Single pooled quarter milk samples were obtained at 6 weeks after treatment and were cultured for the presence of pathogenic bacteria. The percentage of samples with no growth at the post-treatment culture was used as an estimate of the bacteriological cures for each pathogen type and for each treatment group. Somatic cell counts of cows were compared between treatment groups and within pathogen group. The number of cows that completed a full lactation were compared between each treatment group and within each pathogen group. RESULTS: Treatment had no effect upon bacteriological cures, irrespective of pathogen present or the presence of bacteria during the previous lactation. There was no effect of treatment upon somatic cell count except for cows infected with Streptococcus dysgalactiae in which treatment caused a significant lowering of cell counts. This effect was not present in the subsequent lactation. Treatment of chronically infected cows did not alter the probability of a cow completing a full lactation but did improve the probability of newly infected cows being retained for the next lactation. Twenty-eight of 214 treated cows developed clinical mastitis in more than one quarter after treatment, thus indicating a poor technique by farmers for the insertion of intramammary antibiotics. CONCLUSIONS: Treatment during lactation of cows with high somatic cell counts in milk is ineffective in reducing bacterial infections and in reducing somatic cell counts to acceptable numbers.     

Microbiologic investigation of an epizootic of mastitis caused by Serratia marcescens in a dairy herd.

An epizootic of subclinical and clinical mastitis caused by Serratia marcescens was investigated in a 1,000-cow dairy farm in California. Serratia marcescens was isolated from 13 to 18% of composite milk samples obtained from lactating dairy cows. During monthly milk sampling performed during a 4-month period, S marcescens was isolated from 38.8 to 62.3% of composite milk samples obtained from cows from which S marcescens was previously isolated. Few cows infected with S marcescens had evidence of clinical mastitis. Somatic cell count value was associated with isolation of S marcescens. Cows with somatic cell counts greater than 500,000 were 5.48 times as likely to have intramammary infections with S marcescens, compared with cows with somatic cell count less than or equal to 500,000. Lactation number also was associated with S marcescens intramammary infection. After adjusting for the effect of lactation number, cows with high somatic cell count values were 2.98 times as likely to have intramammary infection with S marcescens, compared with cows with low somatic cell counts. Infection with S marcescens was independent of days in lactation, production string, and daily milk production. Eleven months after the beginning of the epizootic, S marcescens was isolated from organic bedding samples obtained from the dairy. Despite numerous attempts, other sources of S marcescens could not be identified on this dairy.     

乳酸链球菌素治疗奶牛乳房炎效果观察

乳酸链球菌素（Nisin）是由乳酸链球菌产生的合有34个氨基酸的抗菌肽,对人体无害。本研究将患临床型乳房炎奶牛92头（107个乳区）和隐性乳房炎奶牛90头（90个乳区）随机分成试验组和对照组。试验组的治疗方法是在患病乳区灌注Nisin;临床型乳房炎以庆大霉素乳房内灌注作对照,隐性乳房炎的对照组不作任何处理。临床型乳房炎的Nisin治疗组细菌学治愈率和临床治愈率分别为60．8％和90．2％,而庆大霉素治疗组则分别为44.6％和91．2％,两者无统计学差异。隐性乳房炎经Nisin治疗后,高体细胞数奶牛的数量和牛奶中NAGase的活性均显著下降,细菌转阴率提高。乳酸菌发酵试验表明,经Nisin乳房内灌注治疗临床型乳房炎后,牛奶在第36小时恢复正常发酵,而庆大霉素治疗则需要72h。     

复方阿莫西林乳房注入剂对临床型奶牛乳房炎的治疗效果

为评价复方阿莫西林乳房注入剂对泌乳期奶牛临床型乳房炎的治疗效果,在甘肃某两个牛场选择70头自然发生的临床型乳房炎奶牛进行临床试验。将患病奶牛随机分为试验组(n=36头)和对照组(n=34头)。试验用药和对照用药分别为郑州百瑞动物药业有限公司和齐鲁动物保健品有限公司提供的复方阿莫西林乳房注入剂。每个感染乳区注入3 g药物,每12 h注射1次,连续用药3 d。在用药前、停药后7 d及14 d采集各组奶牛的奶样进行细菌学检测及乳汁体细胞计数。通过临床观察、细菌清除率及体细胞计数变化对临床疗效进行评价。停药后14 d,试验组和对照组的临床治愈率分别为58.3%和61.8%,细菌总清除率分别为94.12%和93.55%。两组奶样中的SCC在治疗后均显著下降(P<0.01)。两组临床疗效无统计学差异(P>0.05),表明试验用药对奶牛临床型乳房炎具有良好的治疗效果。     

奶牛隐性乳房炎的调查分析

采用体细胞计数(SCC)法对杨凌某奶牛场中60头不同胎次和泌乳时间奶牛隐性乳房炎进行检测,对引起乳房炎的可能诱因进行调查分析,研究该场奶牛隐性乳房炎的发病规律,为本病的防控提供参考。结果表明,受检奶牛隐性乳房炎的检出率为43.3%。1胎～2胎奶牛隐性乳房炎检出率为40.0%,3胎～4胎为46.7%,隐性乳房炎的检出率有随胎次增加而升高的趋势;泌乳时间少于200 d的泌乳牛隐性乳房炎检出率为27.6%,200 d～300 d的为36.4%,300 d～400 d的为41.7%,超过400 d的为50.0%,提示奶牛隐性乳房炎有随泌乳期升高的趋势。本调查显示,奶牛隐性乳房炎的发生与胎次和泌乳时间有显著的相关性,饲养管理和卫生条件是乳房炎发生的重要诱因。     

Development of a Staphylococcus aureus vaccine against mastitis in dairy cows. I. Challenge trials

A vaccine composed of three field isolates of Staphylococcus aureus (S. aureus) derived from cases of mastitis in cows was developed. The vaccine was administered to nine uninfected cows while 10 other cows were used as controls. All cows were challenged with a highly virulent S. aureus strain administered into two quarters of each cow. Quarters were tested for clinical signs, secretion of S. aureus, and somatic cell count (SCC). No systemic effects were observed in any of the cows, vaccinated or control. Vaccinated cows had 70% protection from infection compared with fewer than 10% in the controls. Moreover, all quarters challenged in the vaccinated cows, regardless of whether they were successfully infected or not with S. aureus, exhibited very mild inflammatory reactions, identified by their low SCCs (<100,000).     

Status of bovine mastitis and associated risk factors in subtropical Jeju Island, South Korea

The present investigation was carried out to study the prevalence of mastitis in 136 Holstein cows from a subtropical province of South Korea. Out of 527 milk samples studied, 22.6 % were found positive for mastitis. On animal level, prevalence was estimated at 55.2 %. Late lactating cows were at higher risk for mastitis development as compared to those in early and mid lactations. The study revealed that the risk of an increase in somatic cell count (SSC) and mastitis increased with advanced age and in animals with higher parity. The highest infection rate of 71.4 % was found in the age group >9 years followed by cows with higher than fifth parity (65.5 %). On severity and quarter basis, cows of <3 years of age had higher occurrence (12.5 %) of severe mastitis. From the present study, it may be concluded that a positive relationship exists between increased prevalence of mastitis and high SCC and the advance in age and parity of Holstein cows.     

An outbreak of Streptococcus canis mastitis in a dairy herd in Israel

CASE HISTORY: An increase in the bulk somatic cell count (BSCC) of up to 1,000 x 103 cells/ml occurred in a dairy herd in Israel at the end of 2001 and beginning of 2002. CLINICAL FINDINGS: Bacteriological examination of milk from 69 cows revealed a high prevalence of Streptococcus group G bacteria, identified as S. canis, affecting 38% of cows and 20% of all quarters. Isolates were sensitive to cephalothin and moderately sensitive to penicillin G. Infected cows were separated from the herd, treated with intramammary antibiotics, milked last, and strict hygiene practices were introduced to the milking routine. The pathogen was cleared from the herd and BSCC decreased to 250-350 x 103 cells/ml after 6 months. DIAGNOSIS: Streptococcus canis mastitis. CLINICAL RELEVANCE: Streptococcus canis infection may cause subclinical mastitis and high bulk SCC in dairy herds and be resolved by treatment with intramammary antibiotics and the introduction of strict hygiene practices.     

过瘤胃甜菜碱对隐性乳房炎奶牛生产性能的影响

选择15头体细胞数在100万个/mL以上奶牛,随机分为3组,每组5头,分别在日粮中添加0g/d、18g/d和24g/d过瘤胃甜菜碱,研究其对隐性乳房炎奶牛产奶性能和体细胞数的影响。结果发现:对照组奶牛产奶量与试验前相比,下降了1.04kg,而试验组分别提高了0.52kg和0.88kg;乳脂率、乳蛋白等乳成分略有提高,但差异均不显著。添加过瘤胃甜菜碱组牛奶中体细胞数显著降低,与对照组相比,差异显著(P<0.05)。表明隐性乳房炎奶牛补饲过瘤胃甜菜碱,能够降低牛奶中体细胞数,提高奶牛产奶性能。     

Environmental and managerial determinants of somatic cell counts and clinical mastitis incidence in Ohio dairy herds

A stratified-random sample of 48 Ohio dairy herds participated in a 1-year disease monitoring survey to study herd management and environmental conditions affecting udder infection and clinical mastitis incidence. The mean monthly bulk-tank somatic cell count was used as an indicator of overall udder infection. Clinical incidence was determined by monthly on-farm interviews with the dairy producers. Management and environmental conditions were assessed by direct observation as well as by personal interview of dairy managers. The final multivariable analysis-of-variance model of log bulk-tank somatic cell count had an R² value of 0.43. Lower log bulk-tank somatic cell count was found in herds with hired milkers, a clean and dry cow exercise area, clean teats following milking and fewer milking cows. The number of months spent on pasture was also significant. The final model for clinical mastitis incidence had an R² value of 0.38. Less clinical mastitis was found on farms where straw bedding was used, pre-dip was not used, where there were fewer cows, fewer person-hours per cow were spent milking cows, a greater percentage of calvings occurred in the designated calving facility, and cows spent fewer months per year on pasture. Other potentially important disease determinants could not be included in the final models because of limited sample size relative to the model degrees of freedom (six each).